Based on the 1974 National Study of Philanthropy and 2001-13 data from the longitudinal Philanthropy Panel Study, the report, Women Give 2016: Giving in Young Adulthood: Gender Differences and Changing Patterns Across the Generations (24 pages, PDF), found that estimated giving by single women between the ages of 25 and 47 averaged $244 a year over the 2001-13 period, compared with $216 among single women of the same age in the 1970s. At the same time, overall annual giving by Americans between the ages of 25 and 47 has dropped, from an average of $624 four decades ago to $430, with declines in giving by single men ($492 to $344) and married couples ($721 to $594) accounting for much of the decline. And the percentage of Americans who give large amounts to charity — defined as $100 in the 1970s and $600 today — fell from 22.4 percent to 17.1 percent among single women, from 25 percent to 13.9 percent among single men, and from 51.9 percent to 39 percent among married couples.

Funded by the Bill & Melinda Gates Foundation, the study also found that among married couples who gave large amounts to charity, more women (83.7 percent) report having some influence on household giving decisions today than did their counterparts in the 1970s (73.4 percent). According to the report, millennial and Gen-X couples in which women have a say in giving donated an average of $1,385, up from $986 among their Silent Generation counterparts four decades ago, while among couples in which only the men make giving decisions, average giving fell from $2,203 to $1,269.

"Women's changing roles within society and within the family have implications for philanthropy," said Debra Mesch, director of the Women's Philanthropy Institute and Eileen Lamb O'Gara Chair in Women's Philanthropy at the Lilly Family School of Philanthropy. "Women donors should understand that they have an influence over their personal and household giving. Nonprofit leaders and fundraisers must recognize the importance of single and married women as donors; fundraisers who don't know how to raise money from women simply will not be as successful as Millennials and Gen Xers step fully into their giving."